First of all I’m not RC. Second the shroud proves nothing. It can add nothing to my faith. But if eventually proven a forgery it could prove shattering to the faith of those who rely on signs and man made traditions to validate their faith. The shroud is an interesting curiosity, and someday we will know the truth about it, but meantime we should not let sideshows detract from the Truth.
But if all that you need is contained in the scriptures, that won’t do. Because you must know what it teaches, and this is why Christ gave a Great Commission to his Peter and his apostles to Go forth and Teach. This is to teach ONE truth. Not what you, or I, or Rev Wright, or Joel Ostend, or Jim Jones thinks they can decipher from scripture. That leads to many “truths.”
For us RCs, there is only ONE truth and for this Christ established ONE Church, and the Shroud scientifically affirms our belief in the risen Lord. Affirmation by science is not needed, but then again a blind faith is what other religions claim too. Reason without faith is limited to the horizons of our intellect. Faith without reason is a myth.
We need truth. If science can contribute to this truth why not accept it. if it turns out to be a fake, nothing lost, there are several other sources for verification of Christ’s Resurrection.
Circular reasoning is circular.